216217777278 has 32 divisors (see below), whose sum is σ = 435571668000. Its totient is φ = 71550427136.

The previous prime is 216217777271. The next prime is 216217777283. The reversal of 216217777278 is 872777712612.

It is a super-2 number, since 2×216217777278² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216217777271) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1624750 + ... + 1752782.

It is an arithmetic number, because the mean of its divisors is an integer number (13611614625).

Almost surely, 2^216217777278 is an apocalyptic number.

216217777278 is an abundant number, since it is smaller than the sum of its proper divisors (219353890722).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216217777278 is a wasteful number, since it uses less digits than its factorization.

216217777278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130076.

The product of its digits is 6453888, while the sum is 57.

The spelling of 216217777278 in words is "two hundred sixteen billion, two hundred seventeen million, seven hundred seventy-seven thousand, two hundred seventy-eight".